1. Field of the Invention
The present invention relates to telecommunications and, more particularly, to a method and system for delivering messages directed to a telecommunications user.
2. Description of Related Art
In a telecommunications network, communications destined for a particular user can be routed to an endpoint device at which the user is currently registered. For instance, in instant messaging (IM) systems that allow users to communicate messages in real-time, each user typically has a unique username (generally used in conjunction with a password) that identifies the user to an IM system. Typically, when the user logs into the IM system from a given client station (e.g., personal computer (PC)), the client station, or, more particularly, a client application executed on the station, sends a registration message to an IM server. In turn, the IM server records in an IM registry an association between the user and the client station (e.g., a network address of the client station). This way, if an IM message directed to the user arrives at the server, the server can pass the message on to the client station at which the user is currently registered.
For example, the IM system normally allows users to maintain a list of people, known as a “buddy list”, with whom the users wish to communicate. When another user logs into the IM system and lists the registered user on a “buddy” list, the IM system might send to the other user's station an indication that the registered user is available to receive instant messages. The other user may then send into the network a message destined for the registered user, and the IM server may facilitate delivering the message to the client station associated with the registered user. In one particular example, upon receipt of the message, the IM server could refer to the IM registry to determine the network address of the client station currently associated with the registered user. The IM server could then forward the message to that station's network address.
A problem can arise, however, in a scenario where some time after the user's initial registration with the IM system, the IM registry still indicates that the user is presently associated with the given client station, while, in reality, the user is no longer active at that client station. In one example scenario, the user may physically leave the client station for an indefinite period of time, but may inadvertently forget to log off the IM system to complete an IM session at the station. As a result, the IM server may continue to direct messages destined for the user to the given client station, even though the user may not be active at that station to receive those messages. Similarly, if the user is concurrently registered at multiple client stations, messages directed to the user may be routed to client station(s) at which the user is no longer active.